CN111605447B

CN111605447B - Vehicle seat

Info

Publication number: CN111605447B
Application number: CN202010111148.8A
Authority: CN
Inventors: 永井哲也; 加藤康之; 杉本隆; 小田理; 关隆之介; 饭田健治; 泷波智; 羽田昌敏
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 2019-02-26
Filing date: 2020-02-24
Publication date: 2022-07-15
Anticipated expiration: 2040-02-24
Also published as: US20200269735A1; CN111605447A; EP3702209A1; EP3702209B1; US11472320B2

Abstract

The invention provides a vehicle seat. In a vehicle seat (10), rear suspension members (54; 64; 104; 116) suspend and support a seat cushion (14) on a seat cushion support frame (18) so as to be movable in the left-right direction at two points separated in the left-right direction at end edge portions of a seat back side of the seat cushion (14). The front suspension member (60; 76; 92; 112) suspends and supports the seat cushion (14) on the seat cushion support frame (18) at one position forward of the rear suspension member (54; 64; 104; 116) or at two positions laterally spaced apart.

Description

Vehicle seat

Technical Field

The present invention relates to a vehicle seat, and particularly to a seat cushion.

Background

There is known a vehicle seat that allows a seat cushion to move left and right with respect to a frame of the vehicle seat. For example, japanese patent laid-open No. 2015-229442 shows the movable seat cushion 18 supported to the seat cushion frame 16 via the leaf spring 26. The leaf spring 26 extends rearward from a front end portion of the seat cushion frame 16, and supports the movable seat cushion 18 at a rear end portion. The movable seat cushion 18 can be moved in the left-right direction by the deflection of the leaf spring 26. The leaf spring 26 functions as a beam for cantilever-supporting the movable seat cushion 18. Note that the above-mentioned reference numerals are those used in japanese patent laid-open publication 2015-229442 described below, and are not associated with those used in the description of the embodiments of the present application.

Disclosure of Invention

In japanese patent laid-open publication No. 2015-229442, the weight of a seated occupant or the like acts on a leaf spring cantilever-supporting a movable seat cushion as a bending load. In order to withstand the bending load, the rigidity of the leaf spring needs to be increased. On the other hand, if the rigidity of the leaf spring is increased, the lateral movement of the movable seat cushion is suppressed.

The invention provides a support structure with a simple structure, which allows left and right movement and supports a seat cushion.

One aspect of the present invention relates to a vehicle seat. The vehicle seat device includes: a seat cushion for supporting the buttocks and thighs of a seated person; a seat back that supports the upper body of the seated person from behind; a seat cushion support frame fixedly or slidably mounted to the vehicle body with respect to the vehicle body; a rear suspension member that suspends and supports the seat cushion so as to be movable in the left-right direction on a seat cushion support frame at two points that are separated in the left-right direction at an end edge portion of the seat back side of the seat cushion; and a front suspension member for suspending and supporting the seat cushion at one position forward of the rear suspension member or at two positions laterally spaced apart from each other so as to be movable in the lateral direction.

The bending load acting on the suspension member can be suppressed by suspending and supporting the seat cushion, and the rigidity of the suspension member can be reduced.

In the above aspect, the rear suspension member may be configured such that an interval between upper ends of the right and left rear suspension members is narrower than an interval between lower ends of the rear suspension members. Thereby, the seat cushion can be rotated. That is, the seat cushion is inclined with the right side edge rising when moving rightward, and inclined with the left side edge rising when moving leftward.

In the above aspect, the front suspension member may be provided at both of the positions. This reduces the load on the one front suspension member as compared with the case where the front suspension member is provided at one location, thereby improving durability. In addition, in the case of being provided at one location, the front suspension member must be arranged at the center, but by being provided at two locations, the degree of freedom is increased with respect to the position where the front suspension member is arranged.

In the above aspect, the front suspension members may be provided at the two positions, and an interval between upper ends of the left and right front suspension members may be narrower than an interval between lower ends of the front suspension members. Thereby, the seat cushion can be rotated. That is, the seat cushion is inclined with the right side edge rising when moving rightward, and inclined with the left side edge rising when moving leftward.

In the above aspect, the front suspension member may be disposed in a center portion in the left-right direction of the vehicle seat.

In the above aspect, the seat cushion support frame may include two side members located on the left and right sides, respectively, and a connecting rod extending in the left and right direction and connecting the left and right side members, and an upper end of the rear suspension member may be fixed to the connecting rod.

In the above aspect, the seat back support frame may be coupled to the seat cushion support frame, and the seat back may be supported by the seat back support frame so as to be movable in the lateral direction like a pendulum.

In the above aspect, one or both of the rear suspension member and the front suspension member may be a leaf spring, and one end of the leaf spring may be fixed to a member on the seat cushion support frame side. Thus, the moved seat cushion can be returned by the elastic force of the leaf spring.

In the above aspect, one or both of the rear suspension member and the front suspension member may be a plate spring, an upper end of the plate spring may be fixed to a member on the seat cushion support frame side, a lower end of the plate spring may be fixed to a member on the seat cushion side, a ridge that rises from the plate surface and extends in the longitudinal direction of the plate spring may be formed on the plate surface of the plate spring, and the height of the ridge may gradually decrease from the upper end portion and the lower end portion toward the central portion in the longitudinal direction of the plate spring. In the above aspect, the ridge of the plate spring may have two ridge lines extending in parallel along the longitudinal direction of the plate spring.

In the above aspect, the front suspension member may be a plate spring having an upper end fixed to a member on the seat cushion support frame side and a lower end fixed to a member on the seat cushion side, the plate spring may have an コ -shaped configuration in which the upper end is located forward of the lower end, the plate spring may be open rearward, a ridge may be formed on a plate surface of the plate spring and may extend in a longitudinal direction of the plate spring while rising from the plate surface, a height of the ridge may gradually decrease from an upper end portion and a lower end portion in the longitudinal direction of the plate spring toward a central portion, the ridge may have two ridge lines extending in parallel in the longitudinal direction of the plate spring, and a height of the ridge may be higher in a portion of the ridge line located rearward than in a portion of the ridge line located forward.

In the above aspect, one or both of the rear suspension member and the front suspension member may be a leaf spring, an upper end of the leaf spring may be fixed to a member on the seat cushion support frame side, a lower end of the leaf spring may be fixed to a member on the seat cushion side, the leaf spring may have a thick portion having a large dimension in a thickness direction of at least a part of the leaf spring in a width direction thereof at least both end portions in the longitudinal direction thereof, and the thick portion may gradually decrease in a dimension in the thickness direction from the end portion toward a central portion in the longitudinal direction of the leaf spring.

In the above aspect, the plate spring may be made of a fiber-reinforced resin.

The bending load acting on the suspension member can be suppressed, and the support structure of the seat cushion can be simplified.

Drawings

The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like numerals represent like elements, and wherein:

fig. 1 is a perspective view showing the entire vehicle seat according to the embodiment.

Fig. 2A is a view showing a support structure of a seat cushion, a seat cushion support frame, and a suspended seat cushion, and is a view showing an upper surface side of the seat cushion.

Fig. 2B is a view showing a support structure of the seat cushion, the seat cushion support frame, and the suspended seat cushion, and is a view showing a lower surface side of the seat cushion.

Fig. 3 is a view of the seat cushion and the support structure, which are the moving-side structures, extracted from fig. 2A.

Fig. 4 is a view of the seat cushion support frame and the support structure, which are fixed-side structures, extracted from fig. 2A.

Fig. 5 is a diagram showing the seat cushion and the support structure, which are the moving-side structures, extracted from fig. 2B.

Fig. 6 is a view of the seat cushion support frame and the support structure, which are fixed-side structures, extracted from fig. 2B.

Fig. 7 is a view showing a state of the seat cushion and the seat cushion support frame as viewed from the rear.

Fig. 8 is a diagram illustrating movement of the seat cushion.

Fig. 9 is a view showing another mode of the rear support structure.

Fig. 10 is a view showing another form of the front support structure as viewed obliquely from the rear.

Fig. 11 is a diagram showing another form of the front support structure as viewed obliquely from the front upward direction.

Fig. 12 is a view showing a drop prevention structure of a seat cushion using a wire.

Fig. 13 is a view showing a drop prevention structure using a hook of a seat cushion.

Fig. 14 is a view showing still another embodiment of the front support structure.

Fig. 15 is a perspective view showing an example of the front leaf spring.

Fig. 16 is a front view of the front leaf spring shown in fig. 15.

Fig. 17 is a side view of the front leaf spring shown in fig. 15.

Fig. 18 is a cross-sectional view of the front leaf spring XVIII-XVIII shown in fig. 16.

Fig. 19 is a cross-sectional view taken along line XIX-XIX of the front leaf spring shown in fig. 16.

Fig. 20 is a view showing a stress distribution of the front leaf spring shown in fig. 15.

Fig. 21 is a diagram showing a stress distribution of the front leaf spring having a uniform thickness.

Fig. 22 is a view showing still another embodiment of the rear support structure.

Fig. 23 is a perspective view showing an example of the rear leaf spring.

Fig. 24 is a front view of the rear leaf spring shown in fig. 23.

Fig. 25 is a side view of the rear leaf spring shown in fig. 23.

Fig. 26 is a sectional view taken along line XXVI-XXVI of the rear leaf spring shown in fig. 24.

Fig. 27 is a sectional view taken along line XXVII-XXVII of the rear leaf spring shown in fig. 24.

Fig. 28 is a diagram showing a stress distribution of the rear leaf spring shown in fig. 23.

Fig. 29 is a diagram showing a stress distribution of the rear leaf spring having a uniform thickness.

Fig. 30 is a view showing an example of a cross-sectional shape of the front leaf spring.

Fig. 31 is a view showing an example of a cross-sectional shape of the rear leaf spring.

Detailed Description

Hereinafter, a vehicle seat 10 according to an embodiment of the present invention will be described with reference to the drawings. In the following description, unless otherwise specified, words indicating directions and directions such as front, rear, left, right, up, down, etc., indicate directions and directions relating to an occupant seated in the vehicle seat 10 (hereinafter, referred to as a seated person). In each drawing, the direction of arrow FR is the front, the direction of arrow UP is the upper, and the direction of arrow LH is the left.

Fig. 1 is a perspective view schematically showing a schematic structure of a vehicle seat 10. In fig. 1, a part of the components is omitted. The vehicle seat 10 is a seat for a front seat applied to a vehicle such as a passenger car. The vehicle seat 10 includes: a main frame 12 directly mounted on the vehicle body, and a seat cushion 14 and a seat back 16 movably supported on the main frame 12. In fig. 1, the seat cushion 14 is shown with the cushion pad omitted. The seat cushion 14 supports the buttocks and thighs of the seated person from below, and the seat back 16 supports the upper body of the seated person from behind.

The main frame 12 includes a seat cushion support frame 18 that supports the seat cushion 14 and a seat back support frame 20 that supports the seat back 16. The seat cushion support frame 18 has seat legs 22 at the four corners of the lower portion. The seat legs 22 are disposed on a floor 24 of the vehicle and coupled to a pair of seat rails 26 extending in the front-rear direction of the vehicle. The seat rail 26 includes a lower rail 28 fixed to the floor 24 and an upper rail 30 slidable relative to the lower rail 28, and the seat legs 22 are coupled to the upper rail 30. Thus, the vehicle seat 10 is mounted on the floor panel 24 so as to be slidable in the front-rear direction of the vehicle. The seatback support frame 20 has an inverted U-shape when viewed from the front, and a lower end portion thereof is coupled to a rear end portion of the seat cushion support frame 18. The seat back support frame 20 is rotatably coupled to the seat cushion support frame 18 about an axis extending in the left-right direction. The reclining angle of the seat back 16 can be adjusted by rotating the seat back support frame 20 relative to the seat cushion support frame 18. In addition, the seat back support frame 20 may also be fixedly coupled with the seat cushion support frame 18.

The seat cushion 14 includes a seat pan 32 movably supported by the seat cushion support frame 18 and a cushion pad 34 mounted on the seat pan 32 (see fig. 2A). The structure for supporting the bowl 32 will be described in detail later.

The seat back 16 is supported to a seat back support frame 20. Fig. 1 shows a seat back cushion 36 that a back of a seated person contacts, and a seat back frame (not shown) that mounts the seat back cushion 36 is arranged on a back surface of the seat back cushion 36. The seat back frame is suspended and supported by the seat back support frame 20 through a wire, not shown. Thus, the seat back 16 is supported by the main frame 12 so as to be movable in the left-right direction like a pendulum.

Fig. 2A to 7 are views showing the structures of the seat cushion 14, the seat cushion support frame 18, and their surroundings. Fig. 2A and B are views showing a state in which the seat cushion 14 and the seat-cushion support frame 18 are assembled. In fig. 2A, the state of looking down at the rear portion of the seat cushion 14 is mainly shown, and in fig. 2B, the state of looking up at the front portion is shown. Fig. 2A shows the seat pan 32 and the seat cushion support frame 18 thereunder in a state where the cushion pad 34 is seen through by a single-dot chain line. In each of fig. 3 and the following figures, the cushion pad 34 is omitted. Fig. 3 and 4, and fig. 5 and 6 are views showing the movable portion and the fixed portion separately.

The seat cushion support frame 18 includes a pair of side members 38 disposed on the left and right of the seat cushion 14 and extending in the front-rear direction, and two connecting

rods

40, 42 connecting the left and right side members 38. The side member 38 is a substantially plate-shaped member, and is disposed so that the plate thickness direction is the left-right direction. Of the two connecting

rods

40, 42, the front connecting rod 40 connects them at the front end portion of the side member 38. The rear connecting rod 42 connects the side members 38 at their rear end portions. The seat cushion support frame 18 includes a front member 44 disposed so as to be bridged at the front portion to the left and right side members 38. The front member 44 is a substantially plate-shaped or tray-shaped member, and is disposed so that the plate thickness direction is the vertical direction. The front member 44 is coupled to upper portions of front ends of the left and right side members 38, and projects forward from the front ends of the side members 38 like an eave.

The

support structures

46 and 48 that support the seat cushion 14 are provided at two locations on the left and right of the rear portion of the seat cushion 14, and at one location at the center of the front portion. The support structure 46 provided at the rear portion is referred to as a rear support structure 46, and the support structure 48 provided at the front portion is referred to as a front support structure 48.

The left and right rear support structures 46 each include: a rear support bracket 50, a rear suspension bracket 52, and two rear leaf springs 54. The rear support bracket 50 is fixed in the front-rear, up-down, and left-right directions and is coupled to the rear link 42 so as to be rotatable about an axis extending in the left-right direction. The rear suspension bracket 52 is fixed to the rear end of the bowl 32. The two rear leaf springs 54 are disposed so as to sandwich the rear connecting rod 42, and have upper ends fixed to the rear support bracket 50 and lower ends fixed to the rear suspension bracket 52, respectively. That is, the upper end of the rear leaf spring 54 is fixed to the rear connecting rod 42 by being fixed to the rear support bracket 50, and the lower end is fixed to the bowl 32 by being fixed to the rear suspension bracket 52. The rear leaf spring 54 functions as a rear suspension member that suspends and supports the seat cushion 14 on the seat cushion support frame 18 at a rear edge portion of the rear portion of the seat cushion 14, that is, a side where the seat back 16 is provided. The left and right rear leaf springs 54 are disposed such that the distance between the upper ends is narrower than the distance between the lower ends, and when viewed from the rear, they look ハ -shaped. The rear leaf spring 54 is disposed such that the thickness direction is orthogonal to the front-rear direction. Thereby, the rear portion of the seat cushion 14 is allowed to move in the left-right direction but the movement in the front-rear direction is restricted. The rear leaf spring 54 can be made of, for example, carbon tool steel or stainless steel having a thickness of 0.8 to 1.0 mm.

The rear leaf spring 54 is held at its upper end in the plate thickness direction by two plate members which are part of the rear support bracket 50, and thus the upper end of the rear leaf spring 54 becomes a fixed end. The lower end of the rear leaf spring 54 is sandwiched between two plate members that are part of the rear suspension bracket 52, and thus the lower end of the rear leaf spring 54 becomes a fixed end.

The front support structure 48 includes: a front support bracket 56, a front suspension bracket 58, and a front leaf spring 60. The front support bracket 56 is fixed to the lower surface of the front member 44 of the seat cushion support frame 18, and the front suspension bracket 58 is fixed to the front end of the seat pan 32 and extends forward. The front leaf spring 60 is fixed at its upper end to the front support bracket 56 and at its lower end to the front suspension bracket 58. The front leaf spring 60 functions as a front suspension member that suspends and supports the seat cushion 14 at the front portion thereof on the seat cushion support frame 18. The front leaf spring 60 is disposed vertically when viewed from the front, and is disposed so that the thickness direction thereof is the left-right direction. Thereby, the front portion of the seat cushion 14 is allowed to move in the left-right direction but is restricted from moving in the front-rear direction. The front plate spring 60 can be made of, for example, carbon tool steel or stainless steel having a thickness of 0.8 to 1.0 mm.

The front leaf spring 60 is held at the upper end in the plate thickness direction by the front support bracket 56 and the pressure plate, and the upper end of the front leaf spring 60 becomes a fixed end. The front leaf spring 60 is sandwiched at its lower end in the plate thickness direction by the front suspension bracket 58 and the pressing plate, and thus the lower end of the front leaf spring 60 becomes a fixed end.

The seat cushion 14 is suspended at three points from the seat cushion support frame 18 by the rear support structure 46 and the front support structure 48, and is supported so as to be movable in the left-right direction. And in particular the seat cushion 14, generally rotates about an axis a as shown in fig. 1. By this rotation, the movement of the portion of the seated person near the position through which the axis a of rotation passes can be made smaller than the movement of the portion near the seat cushion 14, specifically, the movement of the buttocks and thighs.

Fig. 8 is a diagram illustrating the movement of the seat cushion 14, and schematically shows the seat cushion 14 and the rear leaf spring 54 in a state viewed from the rear. The seat cushion 14 at the center position in the left-right direction (hereinafter, referred to as a neutral position) and the rear leaf spring 54 at this time are indicated by solid lines. In the neutral position, the seat cushion 14 is disposed horizontally. As described above, the two rear leaf springs 54 are arranged in the form of ハ, and the extended lines of these rear leaf springs 54 intersect at the point O. When the seat cushion 14 moves leftward, the rear leaf spring 54 is arranged in an ハ -shape, and therefore the left end rises and the right end falls as compared with the case of being at the neutral position. Thereby, the seat cushion 14 is tilted rightward. This state is indicated by a one-dot chain line. In addition, when the seat cushion 14 moves to the right, it is inclined to the left conversely. This operation can be regarded as rotation about the point O if it is within a small movement range, for example, a range in which one amplitude is about 3 °.

The upper end and the lower end of the rear leaf spring 54 are fixed ends, and the rear leaf spring 54 is bent by the movement of the seat cushion 14 in the left-right direction. The elastic force generated by this deflection is intended to return the seat cushion 14 to the neutral position. Further, if only the upper end, i.e., the fixed end, of the rear leaf spring 54 is fixed, an elastic force, i.e., a restoring force, for returning to the neutral position is generated.

When the seat cushion 14 moves left and right, if the movement of the front portion of the seat cushion 14 is within a small movement range, it can be regarded as rotation about the upper end of the front leaf spring 60, i.e., the end on the fixed side. The upper and lower ends of the front leaf spring 60 are fixed ends, and when the seat cushion moves leftward and rightward, the front leaf spring 60 bends to generate a restoring force to return to the neutral position. Further, if only the upper end, i.e., the fixed end, of the front leaf spring 60 is fixed, a restoring force to return to the neutral position is generated.

The rotation center of the seat cushion 14 is higher at the rear and lower at the front by the arrangement of the rear leaf spring 54 and the front leaf spring 60. As a result, the axis of rotation of the seat cushion 14 becomes the axis a shown in fig. 1, which is lowered forward. The rear leaf spring 54 and the front leaf spring 60 may be arranged such that the longitudinal direction thereof is orthogonal to the axis a. Further, the present invention may be arranged so that the length direction is perpendicular when viewed from the side.

The rear support structure 46 suspends the seat cushion by the pair of rear leaf springs 54 arranged so as to sandwich the rear connecting rod 42, but is not limited to this, and may be configured to suspend only one rear leaf spring. The rear support structure 62 shown in fig. 9 includes only one rear leaf spring 64. The rear support bracket 66 is fixed in the front-rear, up-down, and left-right directions and is coupled to the rear link 42 so as to be rotatable about an axis extending in the left-right direction. A rear suspension bracket 68 is fixed to a rear edge portion of the bowl 32. The rear leaf spring 64 is fixed at its upper end to the rear support bracket 66 and at its lower end to the rear suspension bracket 68. As with the rear support structure 46, the left and right rear leaf springs 64 are arranged in an ハ -shape when viewed from the rear.

The front support structure 48 is disposed at the center in the left-right direction, but is not limited thereto, and may be disposed at two positions on the left and right as in the rear support structure 46. In this case, the front leaf spring can be arranged in an ハ shape like the rear leaf spring 54. The intersection of the extension lines of the two front leaf springs arranged in an ハ -shape becomes the center of rotation of the front portion of the seat cushion. A line connecting the rotation centers of the front and rear portions serves as a rotation axis of the seat cushion. In this case, the rotation axis can be set to be low in the front and high in the rear.

Fig. 10 and 11 are diagrams showing an example in which the front support structure 70 is disposed at two positions on the left and right. Fig. 10 is a view of the bowl 32 viewed obliquely downward from behind and shown partially cut away from the bottom plate, and fig. 11 is a view of the bowl viewed obliquely upward from in front. The front support structures 70 each include: a front support bracket 72, a front suspension bracket 74, and a front leaf spring 76. The front support bracket 72 is fixed in the front-rear, up-down, and left-right directions and is coupled to the front side link 40 so as to be rotatable about an axis extending in the left-right direction (see fig. 4). The upper end of the front suspension bracket 74 is fixed to a reinforcing rod 78 provided at the front edge of the seat pan 32, and the front suspension bracket 74 extends downward. The front leaf spring 76 is fixed at its upper end to the front support bracket 72 and at its lower end to the lower end of the front suspension bracket 74. The front leaf spring 76 functions as a front suspension member that suspends and supports the seat cushion 14 at the front portion thereof on the seat cushion support frame 18. The left and right front leaf springs 76 are arranged in an ハ -shape when viewed from the front. The front leaf spring 76 is disposed so that the thickness direction is orthogonal to the front-rear direction. Thereby, the front portion of the seat cushion 14 is allowed to move in the left-right direction but is restricted from moving in the front-rear direction. The front plate spring 76 can be made of, for example, carbon tool steel or stainless steel having a thickness of 0.8 to 1.0 mm.

The front leaf spring 76 is held at its upper end in the plate thickness direction by the front support bracket 72 and the pressure plate, and the upper end of the front leaf spring 76 becomes a fixed end. The front leaf spring 76 is sandwiched at its lower end in the plate thickness direction by the front suspension bracket 74 and the pressing plate, and the lower end of the front leaf spring 76 becomes a fixed end.

When a suspension member such as a leaf spring is damaged, it is desirable to prevent the seat cushion 14 from falling down. Fig. 12 and 13 are views showing a member for preventing dropping. Fig. 12 and 13 show a rear support structure in which the front leaf spring 54 of the two leaf springs 54 of the rear support structure 46 is removed and only the rear leaf spring 54 is used. Fig. 12 is a view showing a drop prevention structure using a wire rod. The drop preventing wire 80 is routed to the rear suspension bracket 52 and the rear side link 42. The drop preventing wire 82 is suspended by the rear suspension bracket 52 and the rear support bracket 50. The rear suspension bracket 52 is a member integral with the seat cushion 14, and the rear connecting rod 42 and the rear support bracket 50 are members integral with a part of the seat cushion support frame 18 or the seat cushion support frame 18. Therefore, when the rear leaf spring 54 is damaged, the seat cushion 14 is suspended by the fall-preventing

wires

80 and 82, and is prevented from falling.

Fig. 13 is a view showing a drop prevention structure using a hook. The drop prevention hook 84 is coupled to the rear suspension bracket 52 and is disposed such that the front end thereof is caught by the rear link 42. The rear suspension bracket 52 is a member that is integral with the seat cushion 14, and when the rear leaf spring 54 is damaged, the drop prevention hook 84 is caught by the rear connecting rod 42 to prevent the seat cushion 14 from dropping.

Instead of the leaf springs of the

rear support structures

46, 62 and the

front support structures

48, 70, wires or rods that are movably joined at the upper and lower ends like joints may be used. The wire or the like may be used only for the front support structure, or the wire or the like may be used only for the rear support structure. When a wire or the like is used for both the front support structure and the rear support structure, an elastic member such as a plate spring can be separately used to provide a restoring force to the neutral position. The leaf spring is an elastic member that does not expand or contract in its longitudinal direction but bends only in the thickness direction, and any elastic member having such characteristics may be used instead of the leaf springs of the

rear support structures

46 and 62 and the

front support structures

48 and 70.

The

rear support brackets

50, 66 of the

rear support structures

46, 62 are fixed to the rear connecting rod 42 of the seat cushion support frame 18, but may be fixed to another portion of the seat cushion support frame 18. Similarly, the front support bracket 72 of the front support structure 70 may be fixed to a portion of the seat cushion support frame 18 other than the front connecting rod 40.

Fig. 14 to 19 show another example of the front leaf spring. Fig. 14 is a perspective view showing the front support structure 90. The front support structure 90 has the same structure as the front support structure 70 except for the front leaf spring 92, and the same components are denoted by the same reference numerals and description thereof is omitted. In fig. 14, members indicated by one-dot chain lines are shown in a transparent manner to clarify the shape of the front leaf spring 92. The front leaf spring 92 functions as a front suspension member for suspending and supporting the seat cushion 14 at the front portion thereof to the seat cushion support frame 18, similarly to the front leaf spring 76 described above. The left and right front leaf springs 92 are arranged in an ハ shape when viewed from the front, and are inclined forward when viewed from the side, that is, the upper ends are positioned forward of the lower ends. The front leaf spring 92 is disposed such that the thickness direction is orthogonal to the front-rear direction.

Fig. 15 to 19 show the shape of the front leaf spring 92. Fig. 15 is a perspective view, fig. 16 is a front view showing the widest surface (plate surface), and fig. 17 is a side view seen from the right in fig. 16. FIGS. 18 and 19 are sectional views of the line XVIII-XVIII and the line XIX-XIX shown in FIG. 16, respectively.

As shown in fig. 16, the front leaf spring 92 has an コ -shape, and is disposed so that the open side of the コ -shape faces rearward when attached as shown in fig. 14. The front leaf spring 92 includes: a base plate portion 94 having a predetermined uniform thickness, and a ridge 96 rising from the base plate portion 94 and extending in the longitudinal direction of the front leaf spring 92. The thickness of the base plate portion 94 is defined by the thinnest portion of the front leaf spring 92, and the ridge 96 is raised from a plate surface 94a orthogonal to the thickness direction. In the front leaf spring 92, the ridges 96 are formed on both front and back surfaces of the base plate portion 94, but may be formed only on one surface. The height of the ridge 96, i.e., the distance from the plate surface 94a to the apex, is higher at the ends on both sides in the longitudinal direction of the front leaf spring 92, and gradually decreases toward the center. By making the ridge 96 higher at the end, that is, by making the thickness of the front leaf spring 92 thicker, the strength of the end where the stress is concentrated is increased, while making the center portion thinner, the flexure of the entire front leaf spring 92 is ensured.

As shown in fig. 18, the ridge 96 is provided at the center in the width direction of the front leaf spring 92, and the edges of the front leaf spring 92 on both sides in the width direction are thinned. This increases the stress in the ridge 96 and decreases the stress in the edge. Cracks may easily occur in the edge portions, and the stress at the edge portions is reduced, whereby the front leaf spring 92 can be prevented from being broken due to the cracks occurring from the edge portions. In addition, the ridge 96 has two ridge lines 98 extending in parallel along the longitudinal direction. By providing two ridge lines 98 separated in the width direction, the rigidity against torsion can be improved as compared with the case where the ridge line is one. The height of the ridge 96 can be set so that the portion of the ridge 98R located rearward is higher than the portion of the ridge 98F located forward. In the front leaf spring 92, the stress at the corner portion 100 inside the コ is increased, and the stress at the corner portion 100 can be further reduced by increasing the portion of the rear ridge 98R.

The front leaf spring 92 may be made of fiber-reinforced resin, particularly carbon fiber-reinforced resin. The reinforcing fibers may be unidirectional fiber-reinforced resin extending in the longitudinal direction of the front leaf spring 92.

Fig. 20 is a diagram showing the distribution of stress generated when the front leaf spring 92 is flexed, and fig. 21 shows the distribution of stress of the front leaf spring 92B having a uniform thickness as a comparative example. The double-hatched portion is a portion having the highest stress, and the stresses of the hatched portion and the halftone dot portion are sequentially reduced. It is understood that, when the thickness is uniform (see fig. 21), a high stress is generated in the corner portion 100, but when the ridge 96 is provided, the stress in the portion of the ridge 96 is increased, while the stress in the portion of the edge such as the corner portion 100 is decreased.

Fig. 22 to 27 show another example of the rear leaf spring. Fig. 22 is a perspective view showing the rear support structure 102. The rear support structure 102 has the same structure as the

rear support structures

46 and 62 except for the rear leaf spring 104, and the same components are denoted by the same reference numerals and the description thereof is omitted. In the rear support structure 102, one rear leaf spring 104 is disposed behind the rear link 42. The rear leaf spring 104 functions as a rear suspension member for suspending and supporting the seat cushion 14 at the rear portion thereof by the seat cushion support frame 18, similarly to the rear leaf spring 54 described above. The left and right rear leaf springs 104 are arranged in an ハ shape when viewed from the front, and are inclined forward when viewed from the side, that is, the upper ends are positioned forward relative to the lower ends.

Fig. 23 to 27 show the shape of the rear leaf spring 104. Fig. 23 is a perspective view, fig. 24 is a front view showing a widest surface (plate surface), and fig. 25 is a side view seen from the right in fig. 24. Fig. 26 and 27 are cross-sectional views based on the lines XXVI to XXVI and XXVII to XXVII shown in fig. 24, respectively.

As shown in fig. 23, the rear leaf spring 104 has an elongated rectangular shape. Further, the rear leaf spring 104 includes: a base plate portion 106 having a predetermined uniform thickness, and a ridge 108 rising from the base plate portion 106 and extending in the longitudinal direction of the rear leaf spring 104. The thickness of the substrate portion 106 is defined by the thinnest portion of the rear leaf spring 104, and the ridge 108 is raised from the plate surface 106a perpendicular to the thickness direction. In the rear leaf spring 104, the ridges 108 are formed on both front and rear surfaces of the base plate 106, but may be formed only on one surface. The height of the ridge 108, i.e., the distance from the plate surface 106a to the apex, is higher at the end portions on both sides in the longitudinal direction of the rear leaf spring 104, and gradually decreases toward the center portion. By making the ridges 108 higher at the end portions, that is, by making the rear leaf spring 104 thicker, the strength of the end portions where stress concentrates is increased, while the bending of the entire rear leaf spring 104 is ensured by making the central portion thinner.

As shown in fig. 26, the ridge 108 is provided at the center in the width direction of the rear leaf spring 104, and the edge portions of the rear leaf spring 104 on both sides in the width direction are thinned. This increases the stress in the ridge 108 and decreases the stress in the edge. Cracks may easily occur in the edge portions, and the stress in the edge portions is reduced, whereby the rear leaf spring 104 can be prevented from being broken by the cracks occurring in the edge portions. In addition, the ridge 108 has two ridge lines 110 extending in parallel in the longitudinal direction. By providing two ridge lines 110 separated in the width direction, the rigidity against torsion can be improved as compared with the case where the ridge line is one. The heights of the two ridge lines 110 can be set to be substantially the same.

The rear leaf spring 104 may be made of fiber-reinforced resin, particularly carbon fiber-reinforced resin. The reinforcing fibers may be unidirectional fiber-reinforced resin extending in the longitudinal direction of the rear plate spring 104.

Fig. 28 is a diagram showing the distribution of stress generated when the rear leaf spring 104 is flexed, and fig. 29 shows the distribution of stress of the rear leaf spring 104B having a uniform thickness as a comparative example. The double-hatched portion is a portion having the highest stress, and the stresses of the hatched portion and the halftone dot portion are sequentially reduced. It is understood that, when the thickness is uniform (see fig. 29), a high stress is generated over the entire width of the end portion, but when the ridge 108 is provided, the stress of the portion of the ridge 108 is increased, while the stress of the portion of the edge is decreased.

Fig. 30 is a view showing a cross-sectional shape of the front leaf spring 112. The front leaf spring 112 has the same shape as the front leaf spring 92 described above except for the shape of the cross section. The ridge line of the cross-sectional shape of the front leaf spring 92 indicated by the one-dot chain line is formed at an acute angle, but in the front leaf spring 112, the ridge line 114 is formed smoothly. Fig. 31 is a view showing a cross-sectional shape of the rear leaf spring 116. The rear leaf spring 116 has the same shape as the rear leaf spring 104 described above except for the shape of the cross section. The ridge line of the cross-sectional shape of the rear leaf spring 104 shown by the one-dot chain line is formed at an acute angle, but in the rear leaf spring 116, the ridge line 118 is formed smoothly. When the prepreg is laminated to produce the fiber-reinforced resin leaf spring, the smooth ridge line is advantageous.

The front leaf spring and the rear leaf spring may have a uniform thickness in the width direction, and may have a shape in which the end portions are thick and the central portion is thin in the longitudinal direction.

The vehicle seat 10 is a front seat that is slidable in the front-rear direction and is adjustable in the angle of the seat back, but the support structure of the seat cushion and the seat back may be applied to a rear seat that is slidable or the like, or a seat that does not have one or both of a sliding function and an angle adjustment function of the seat back, such as a rear seat of a car-type passenger vehicle.

Claims

1. A vehicle seat is characterized by comprising:

a seat cushion for supporting the buttocks and thighs of a seated person;

a seat back that supports the upper body of the seated person from behind;

a seat cushion support frame fixedly or slidably attached to a vehicle body and having two side members located on left and right sides, respectively, and a connecting rod extending in the left-right direction and connecting the side members, wherein a rear support bracket is fixed in the front-rear, up-down, and left-right directions and is coupled to a rear connecting rod so as to be rotatable about an axis extending in the left-right direction;

rear suspension members that are provided at two positions separated from each other in the left-right direction on end edge portions on the seat back side of the seat cushion, and whose upper ends are fixed to the rear support bracket so as to suspend and support the seat cushion on the seat cushion support frame so as to be movable in the left-right direction; and

and a front suspension member that suspends and supports the seat cushion by suspending the seat cushion in a movable manner in a left-right direction at one point forward of the rear suspension member or at two points laterally spaced apart from each other.

2. The vehicle seat according to claim 1, wherein,

the interval of the upper ends of the rear suspension members is narrower than the interval of the lower ends of the rear suspension members.

3. The vehicle seat according to claim 1, wherein,

the front suspension member is provided at the two locations.

4. The vehicle seat according to claim 2, wherein,

the front suspension member is provided at the two positions, and the interval between the upper ends of the front suspension member is narrower than the interval between the lower ends of the front suspension member.

5. The vehicle seat according to claim 2, wherein,

the front suspension member is located at a center portion in the left-right direction of the vehicle seat.

6. The vehicle seat according to claim 1, wherein,

the vehicle seat includes a seat back support frame coupled to the seat cushion support frame, and the seat back is supported by the seat back support frame so as to be movable in the lateral direction like a pendulum.

7. The vehicle seat according to any one of claims 1 to 6,

one or both of the rear suspension member and the front suspension member are leaf springs, and one end of each leaf spring is fixed to a support bracket on the seat cushion support frame side.

8. The vehicle seat according to any one of claims 1 to 6,

one or both of the rear suspension member and the front suspension member are leaf springs, an upper end of each leaf spring is fixed to a support bracket on the seat cushion support frame side, a lower end of each leaf spring is fixed to a support bracket on the seat cushion side, a ridge that rises from the plate surface and extends in the longitudinal direction of the leaf spring is formed on the plate surface of the leaf spring, and the height of the ridge gradually decreases from the upper end portion and the lower end portion toward the central portion in the longitudinal direction of the leaf spring.

9. The vehicle seat according to claim 8,

the ridge of the plate spring has two ridge lines extending in parallel along the longitudinal direction of the plate spring.

10. The vehicle seat according to claim 4, wherein,

the front suspension member is a plate spring having an upper end fixed to the support bracket on the seat cushion support frame side and a lower end fixed to the support bracket on the seat cushion side, the upper end of the plate spring is located at the front with respect to the lower end, the plate spring is in an コ -shaped configuration that opens rearward, a ridge that is raised from the plate surface and extends in the longitudinal direction of the plate spring is formed on the plate surface of the plate spring, the height of the ridge gradually decreases from the upper end portion and the lower end portion in the longitudinal direction of the plate spring toward the central portion, the ridge has two ridge lines that extend in parallel in the longitudinal direction of the plate spring, and the height of the ridge line at the rear is higher than the ridge line at the front.

11. The vehicle seat according to any one of claims 1 to 6,

one or both of the rear suspension member and the front suspension member are leaf springs, upper ends of the leaf springs are fixed to the support bracket on the seat cushion support frame side, lower ends of the leaf springs are fixed to the support bracket on the seat cushion side, the leaf springs have thick portions at least at both ends in the longitudinal direction of the leaf springs, the thick portions having a large dimension in the thickness direction of at least a part of the leaf springs in the width direction, and the dimension of the thick portions in the thickness direction of the leaf springs in the longitudinal direction gradually decreases from the ends toward the center.

12. The vehicle seat according to claim 7,

the plate spring is made of fiber-reinforced resin.

13. The vehicle seat according to claim 8, wherein,

the plate spring is made of fiber-reinforced resin.

14. The vehicle seat according to claim 9,

the plate spring is made of fiber-reinforced resin.

15. The vehicle seat according to claim 10,

the plate spring is made of fiber-reinforced resin.

16. The vehicle seat according to claim 11, wherein,

the plate spring is made of fiber-reinforced resin.